Physical quantity sensor, electronic apparatus and vehicle

Patent metadata

Field	Value
Publication number	US-11099206-B2
Application number	US-201916665809-A
Country	US
Kind code	B2
Filing date	Oct 28, 2019
Priority date	Oct 29, 2018
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

The physical quantity sensor includes a substrate of which thickness direction is in the direction along the Z axis, and a sensor element provided on the substrate to detect a physical quantity, wherein the sensor element includes a movable part which is displaced in a direction along the X axis that is an axis for measuring the physical quantity with respect to the substrate, and a fixed electrode fixed to the substrate, and the movable part includes a movable electrode disposed to face the fixed electrode in the direction along the X axis, and a mass portion that supports the movable electrode and has a longer length than the movable electrode in a direction along the Z axis.

First claim

What is claimed is:

1. A physical quantity sensor comprising:
a substrate of which a thickness direction is in a direction along a Z axis, when three axes orthogonal to one another are taken as an X axis, a Y axis, and the Z axis; and
a sensor element provided on the substrate to measure a physical quantity,
wherein the sensor element includes
a movable part which displaces in a direction along the X axis that is an axis for measuring the physical quantity with respect to the substrate, and
a fixed electrode fixed to the substrate, and
the movable part includes
a movable electrode disposed to face the fixed electrode in the direction along the X axis, and
a mass portion that supports the movable electrode and has a longer length than the movable electrode in the direction along the Z axis,
the movable part comprising a frame shape that surrounds the fixed electrode and includes a base portion comprising the mass portion, the base portion supporting the moveable electrode.

2. The physical quantity sensor according to claim 1 ,
wherein the mass portion has a longer length than the fixed electrode along the Z axis direction.

3. The physical quantity sensor according to claim 2 ,
wherein the movable electrode and the fixed electrode have equal lengths along the Z axis direction.

4. The physical quantity sensor according to claim 1 ,
wherein the sensor element includes
a fixed portion fixed to the substrate, and
a spring that connects the fixed portion and the movable part.

5. The physical quantity sensor according to claim 4 ,
wherein the spring has a length shorter than the mass portion in the direction along the Z axis direction.

6. The physical quantity sensor according to claim 1 ,
wherein the fixed electrode includes
a first fixed electrode and a second fixed electrode disposed side by side in a direction along the Y axis,
the first fixed electrode includes
a first trunk portion, and
a plurality of first fixed electrode fingers extending from the first trunk portion to both sides in the direction along the Y axis, and
the second fixed electrode includes
a second trunk portion, and
a plurality of second fixed electrode fingers extending from the second trunk portion to both sides in the direction along the Y axis.

7. The physical quantity sensor according to claim 6 ,
wherein each of the first trunk portion and the second trunk portion extends along an axis inclined with respect to the X axis and the Y axis.

8. The physical quantity sensor according to claim 6 ,
wherein the first trunk portion and the second trunk portion are line symmetrical with respect to the X axis.

9. The physical quantity sensor according to claim 6 ,
wherein a plurality of the first fixed electrode fingers extending from the first trunk portion to a side of the second trunk portion, and a plurality of the second fixed electrode fingers extending from the second trunk portion to a side of the first trunk portion are disposed along the X axis, with a length in the Y axis direction gradually increasing toward one side in the direction along the X axis, and
a plurality of the first fixed electrode fingers extending from the first trunk portion to a side opposite to the second trunk portion, and a plurality of the second fixed electrode fingers extending from the second trunk portion to a side opposite to the first trunk portion are disposed along the X axis, with a length in the Y axis direction gradually increasing toward the other side in the direction along the X axis.

10. The physical quantity sensor according to claim 9 ,
wherein the movable electrode finger is located between a pair of the first fixed electrode fingers adjacent to each other in the X axis direction,
a separation distance between one first fixed electrode finger and the movable electrode finger is different from a separation distance between the other first fixed electrode finger and the movable electrode finger,
the movable electrode finger is located between a pair of the second fixed electrode fingers adjacent in the X axis direction, and
a separation distance between one second fixed electrode finger and the movable electrode finger is different from a separation distance between the other second fixed electrode finger and the movable electrode finger.

11. An electronic apparatus comprising the physical quantity sensor according to claim 1 .

12. A vehicle comprising the physical quantity sensor according to claim 1 .

Assignees

• Seiko Epson Corp

Inventors

• Matsuura Yoshiyuki

Classifications

• G01P15/0802

  Details · CPC title

• G01P15/125 Primary

  by capacitive pick-up · CPC title

• G01P2015/0848

  using a plurality of mechanically coupled spring-mass systems, the sensitive direction of each system being different · CPC title

• G01P15/18

  in two or more dimensions · CPC title